Some people use the md driver on laptops and use the suspend and
resume functionality. Since it is essential that submitting of
new I/O requests stops before a hibernation image is created,
interrupt the md resync and reshape actions if the system is
being frozen. Note: the resync and reshape will restart after
the system is resumed and a message similar to the following
will appear in the system log:
md: md0: data-check interrupted.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Reviewed-by: Shaohua Li <shli@xxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Tested-by: Martin Steigerwald <martin@xxxxxxxxxxxx>
Cc: linux-raid@xxxxxxxxxxxxxxx
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
---
drivers/md/md.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
drivers/md/md.h | 8 ++++++++
2 files changed, 57 insertions(+), 1 deletion(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index b99584e5d6b1..8b2fc750f97f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -66,6 +66,8 @@
#include <linux/raid/md_u.h>
#include <linux/slab.h>
#include <linux/percpu-refcount.h>
+#include <linux/freezer.h>
+#include <linux/suspend.h>
#include <trace/events/block.h>
#include "md.h"
@@ -7439,6 +7441,7 @@ static int md_thread(void *arg)
*/
allow_signal(SIGKILL);
+ set_freezable();
while (!kthread_should_stop()) {
/* We need to wait INTERRUPTIBLE so that
@@ -7449,7 +7452,7 @@ static int md_thread(void *arg)
if (signal_pending(current))
flush_signals(current);
- wait_event_interruptible_timeout
+ wait_event_freezable_timeout
(thread->wqueue,
test_bit(THREAD_WAKEUP, &thread->flags)
|| kthread_should_stop() || kthread_should_park(),
@@ -8944,6 +8947,8 @@ static void md_stop_all_writes(void)
int need_delay = 0;
for_each_mddev(mddev, tmp) {
+ mddev->frozen_before_suspend =
+ test_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
if (mddev_trylock(mddev)) {
if (mddev->pers)
__md_stop_writes(mddev);
@@ -8963,6 +8968,47 @@ static void md_stop_all_writes(void)
mdelay(1000*1);
}
+static void md_restore_frozen_flag(void)
+{
+ struct list_head *tmp;
+ struct mddev *mddev;
+
+ for_each_mddev(mddev, tmp) {
+ if (mddev->frozen_before_suspend)
+ set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ else
+ clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ }
+}
+
+/*
+ * Ensure that neither resyncing nor reshaping occurs while the system is
+ * frozen.
+ */
+static int md_notify_pm(struct notifier_block *bl, unsigned long state,
+ void *unused)
+{
+ pr_debug("%s: state = %ld\n", __func__, state);
+
+ switch (state) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_SUSPEND_PREPARE:
+ case PM_RESTORE_PREPARE:
+ md_stop_all_writes();
+ break;
+ case PM_POST_HIBERNATION:
+ case PM_POST_SUSPEND:
+ case PM_POST_RESTORE:
+ md_restore_frozen_flag();
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block md_pm_notifier = {
+ .notifier_call = md_notify_pm,
+};
+
static int md_notify_reboot(struct notifier_block *this,
unsigned long code, void *x)
{
@@ -9009,6 +9055,7 @@ static int __init md_init(void)
md_probe, NULL, NULL);
register_reboot_notifier(&md_reboot_notifier);
+ register_pm_notifier(&md_pm_notifier);
raid_table_header = register_sysctl_table(raid_root_table);
md_geninit();
@@ -9248,6 +9295,7 @@ static __exit void md_exit(void)
unregister_blkdev(MD_MAJOR,"md");
unregister_blkdev(mdp_major, "mdp");
+ unregister_pm_notifier(&md_pm_notifier);
unregister_reboot_notifier(&md_reboot_notifier);
unregister_sysctl_table(raid_table_header);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index d8287d3cd1bf..727b3aef4d26 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -356,6 +356,14 @@ struct mddev {
*/
int recovery_disabled;
+ /* Writes are stopped before hibernation, suspend and restore by
+ * calling md_stop_all_writes(). That function sets the
+ * MD_RECOVERY_FROZEN flag. The value of that flag is saved before
+ * writes are stopped such that it can be restored after hibernation,
+ * suspend or restore have finished.
+ */
+ bool frozen_before_suspend;
+
int in_sync; /* know to not need resync */
/* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so
* that we are never stopping an array while it is open.
--
2.14.2
